Electronic devices, for example, smart phones and tablet computers, need to be charged usually at daily basis in order to keep them operative. Especially earlier electronic devices included a device manufacturer specific charger and a charger port. Recently, a technology standard called Universal Serial Bus type-C (USB type-C and/or USB-C) was agreed between various device manufacturers and software providers. Traditionally it has been possible to convey operating or charging power only in one direction via a USB cable. The strength of the USB-C is that it is able to convey both operating or charging power and data in both directions. This also means that practically any electronic device connected to another electronic device using the USB-C may act as a charging entity. As an example, if a monitor is connected to a computer using the USB-C, only the monitor needs to be connected to the electric power network, and the monitor provides operating power to the computer via the USB-C.